using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;

namespace Nikse.SubtitleEdit.Core.SubtitleFormats
{
    public class CaptionAssistant : SubtitleFormat
    {
        public override string Extension => ".cac";

        public override string Name => "Caption Assistant";

        private static string ToTimeCode(TimeCode time)
        {
            return time.ToHHMMSSFF();
        }

        private static TimeCode DecodeTimeCode(string s)
        {
            var parts = s.Split(new[] { ':', ';' }, StringSplitOptions.RemoveEmptyEntries);
            var hour = int.Parse(parts[0]);
            var minutes = int.Parse(parts[1]);
            var seconds = int.Parse(parts[2]);
            var frames = int.Parse(parts[3]);

            int milliseconds = (int)Math.Round(((TimeCode.BaseUnit / Configuration.Settings.General.CurrentFrameRate) * frames));
            if (milliseconds > 999)
            {
                milliseconds = 999;
            }

            return new TimeCode(hour, minutes, seconds, milliseconds);
        }

        public override string ToText(Subtitle subtitle, string title)
        {
            string xmlStructure =
                "<?xml version=\"1.0\" encoding=\"utf-8\" ?>" + Environment.NewLine +
                "<CaptionAssistant><CaptionData></CaptionData></CaptionAssistant>";

            var xml = new XmlDocument();
            xml.LoadXml(xmlStructure);
            xml.XmlResolver = null;
            var cd = xml.DocumentElement.SelectSingleNode("CaptionData");
            foreach (Paragraph p in subtitle.Paragraphs)
            {
                XmlNode paragraph = xml.CreateElement("CaptionDetail");

                XmlAttribute start = xml.CreateAttribute("PositionIn");
                start.InnerText = ToTimeCode(p.StartTime);
                paragraph.Attributes.Append(start);

                XmlAttribute end = xml.CreateAttribute("PositionOut");
                end.InnerText = ToTimeCode(p.EndTime);
                paragraph.Attributes.Append(end);

                XmlAttribute text = xml.CreateAttribute("CaptionText");
                text.InnerText = HtmlUtil.RemoveHtmlTags(p.Text, true);
                paragraph.Attributes.Append(text);

                XmlAttribute align = xml.CreateAttribute("Align");
                if (p.Text.StartsWith("{\\an1}", StringComparison.Ordinal) || p.Text.StartsWith("{\\an4}", StringComparison.Ordinal) || p.Text.StartsWith("{\\an7}", StringComparison.Ordinal))
                {
                    align.InnerText = "Left";
                }
                else if (p.Text.StartsWith("{\\an3}", StringComparison.Ordinal) || p.Text.StartsWith("{\\an6}", StringComparison.Ordinal) || p.Text.StartsWith("{\\an9}", StringComparison.Ordinal))
                {
                    align.InnerText = "Right";
                }
                else
                {
                    align.InnerText = "Center";
                }

                paragraph.Attributes.Append(align);

                XmlAttribute captionType = xml.CreateAttribute("CaptionType");
                captionType.InnerText = "608CC1";
                paragraph.Attributes.Append(captionType);

                cd.AppendChild(paragraph);
            }

            return ToUtf8XmlString(xml);
        }

        public override void LoadSubtitle(Subtitle subtitle, List<string> lines, string fileName)
        {
            _errorCount = 0;

            var sb = new StringBuilder();
            lines.ForEach(line => sb.AppendLine(line));

            string allText = sb.ToString();
            if (!allText.Contains("<CaptionAssistant>") || !allText.Contains("<CaptionData>"))
            {
                return;
            }

            var xml = new XmlDocument { XmlResolver = null };
            try
            {
                xml.LoadXml(allText);
            }
            catch (Exception exception)
            {
                System.Diagnostics.Debug.WriteLine(exception.Message);
                _errorCount = 1;
                return;
            }

            if (xml.DocumentElement == null)
            {
                _errorCount = 1;
                return;
            }

            foreach (XmlNode node in xml.DocumentElement.SelectNodes("CaptionData/CaptionDetail"))
            {
                try
                {
                    if (node.Attributes != null)
                    {
                        string text = node.Attributes.GetNamedItem("CaptionText").InnerText.Trim();

                        if (node.Attributes.GetNamedItem("Align") != null)
                        {
                            string align = node.Attributes.GetNamedItem("Align").InnerText.Trim();
                            if (align.Equals("left", StringComparison.OrdinalIgnoreCase))
                            {
                                text = "{\\an1}" + text;
                            }
                            else if (align.Equals("right", StringComparison.OrdinalIgnoreCase))
                            {
                                text = "{\\an3}" + text;
                            }
                        }

                        string start = node.Attributes.GetNamedItem("PositionIn").InnerText;
                        string end = node.Attributes.GetNamedItem("PositionOut").InnerText;
                        subtitle.Paragraphs.Add(new Paragraph(DecodeTimeCode(start), DecodeTimeCode(end), text));
                    }
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine(ex.Message);
                    _errorCount++;
                }
            }
            subtitle.Renumber();
        }

    }
}